For example, when an infrastructure cooperative service is provided at each service-target intersection, infrastructure information is received through roadside-to-vehicle communication using a beacon arranged in the vicinity of the intersection, and signal information or the like included in the infrastructure information is used. In a roadside communication system described in Patent Literature 1, signal information is created on the basis of a traffic light color displayed currently, the elapsed time of the light color, and the lighting time of each traffic light color. Simultaneously, the required communication time until a roadside device transmits the signal information to an in-vehicle device after the signal information is transmitted to the roadside device is calculated, the signal information is corrected on the basis of the required communication time, and the corrected signal information is transmitted from the roadside device to the in-vehicle device.